Patient monitoring can take a variety of forms and can gather a wide variety of physiological data. The display of such data, including what is displayed and how it is displayed, can affect the ability of caregivers such as doctors and nurses to interpret and act on it. For example, intracranial pressure is a standard monitoring modality for traumatic brain injury patients. Medical guidelines may prescribe threshold values for intracranial pressure. The guidelines of the Brain Trauma Foundation, for example, indicate that clinical action should be taken to reduce intracranial pressure if it exceeds 20-25 mmHg. However, numerous factors can cause transient changes to intracranial pressure, including patient physiology, monitoring system noise, and actions taken by a caregiver.
To monitor a patient, caregivers use monitoring devices such as the Codman ICP Express, which is shown in FIG. 1. As shown, it has a display of intracranial pressure and a display of systolic and diastolic values for the intracranial pressure, as well as an alarm. A caregiver can look at the display to ascertain the intracranial pressure. Caregivers also use charts, e.g., a caregiver can manually record an event in a chart associated with a patient.
Improved methods and devices for display of intracranial pressure would allow for a more complete picture of a patient's condition, e.g., to assist in clinical decision making. Moreover, such considerations are applicable not just to intracranial pressure, but to a wide variety of patient monitoring modalities involving other physiological parameters. Accordingly, there is a need for improved devices and methods for monitoring a patient and for monitoring and displaying the value of a physiological parameter.